Usage of shipping pallets made predominantly of corrugated paperboard material is widespread, primarily because of their low cost, recyclability, and cleanliness. Typically, such pallets employ longitudinally extending, transversely spaced stringers, which are made from folded pieces of corrugated paperboard. Such pallets also may employ transversely extending, longitudinally spaced decking members, which also are made from folded pieces of corrugated paperboard.
As described above, shipping pallets made predominantly of paperboard material, such as corrugated paperboard, are exemplified in Schmidtke U.S. Pat. No. 4,792,325, Quasnick U.S. Pat. No. 4,867,074, and Smith U.S. Pat. No. 5,001,991. Similar pallets made predominantly of corrugated paperboard are available commercially from Gate Pallet Systems, Inc. of Crown Point, Ind., under its PAYLOAD trademark.
Other pallets of related interest are disclosed in Hermitage U.S. Pat. No. 2,728,545, Houle U.S. Pat. No. 3,131,656, Gifford U.S. Pat. No. 3,464,371, Childs U.S. Pat. No. 3,659,534, Roberts U.S. Pat. No. 3,683,822, Melli U.S. Pat. No. 4,563,377, British Patent Specification No. 996,516, German Patent No. 1,250,352, and Swiss Patent No. 512,367.
As disclosed in Smith U.S. Pat. No. 5,001,991, it is known to increase the lateral stability and load-carrying capacity of such a pallet by means of tubular reinforcing pieces, which have slots interengaging with slots in the stringers. It is disclosed therein that tightly wound paper tubing, such as that used for cores for paper rolls, is a suitable material for such pieces.
In U.S. patent application Ser. No. 08/074,942, supra, several embodiments of an improved pallet are disclosed, in which at least one longitudinally extending stringer and at least one transversely extending brace are employed in a novel combination. As disclosed therein, a notch in the stringer interengages with a notch in the brace, and the notches are dimensioned so that the stringer and the brace are substantially coplanar at their upper and lower edges. Each embodiment of the improved pallet, as disclosed therein, is noteworthy for its lateral stability and load-carrying capacity.
In U.S. patent application Ser. No. 08/201,345, supra, two embodiments of a further improved pallet are disclosed. As disclosed therein, each brace has a generally planar upper edge, which may be adhesively secured to a generally planar lower edge of a decking member. Each embodiment of the further improved pallet, as disclosed therein, exhibits improvements in its lateral stability and load-carrying capacity.
This invention has resulted from efforts further to increase the lateral stability and load-carrying capacity of a shipping pallet that may be predominantly made of paperboard material.